Although angular misclosures cannot be directly computed for link traverses,
the angles can still be checked. The direction of the first line may be determined
from two intervisible stations with a known azimuth between them, or
from a sun or Polaris observation, as described in Appendix C. Observed angles
are then applied to calculate the azimuths of all traverse lines.The last line’s computed
azimuth is compared with its known value, or the result obtained from another
sun or Polaris observation, On long traverses, intermediate lines can be
checked similarly. In using sun or Polaris observations to check angles on traverses
of long east-west extent, allowance must be made for convergence of meridians.
This topic is discussed in Section 19.12.2.